The present invention relates to vehicles constructed to travel in militarily hostile environments. More particularly, the present invention relates to vehicles intended to operate in the vicinity of minefields.
Few vehicles are constructed to withstand the destructive forces of landmines which can be encountered in combat regions during and after hostilities. For example, extremely heavy and expensive tanks have been constructed, such as the United States"" M1 Abrams tank which attempts to withstand landmine blasts by constructing the vehicle with several inches of steel armor. Unfortunately, such vehicles are extremely large, heavy and lack maneuverability and thus are not suited for many geographical locations. The vehicles are also extremely expensive and thus are not economically feasible for many combat functions. Moreover, even though such heavy tanks are constructed to withstand and operate after encountering antipersonnel landmines which are designed to incapacitate humans but not vehicles, heavy tanks cannot typically withstand the direct blast of an antitank landmine. After encountering such a landmine, a tank will typically protect its occupants but lose a track, resulting in the tank being completely immobile. Where the tank is in combat, any occupants within the tank are at great risk as it is impossible for them to flee from the combat location while the tank is immobilized.
Smaller combat vehicles such as the HUMVEE cannot even withstand the blast from an antipersonnel landmine. Smaller combat vehicles are typically not provided with metal tracks or thick armor and become immobilized upon impacting either an antitank landmine or an antipersonnel landmine. Again, if this occurs in a combat setting, occupants with the vehicle become a stationary target more easily killed during enemy fire. Anecdotally, military personnel have expressed reluctance to enter into some military vehicles during combat due to their reputation for becoming immobile and dangerously vulnerable after a vehicle""s wheel encounters a landmine or other ordnance.
The global landmine crisis has also created a hostile environment even though military combat may no longer exist in a particular region. It is estimated that there are between 60 and 70 million landmines deployed in the ground located in more than 70 countries. At present, the United Nations estimates that landmines kill 24,000 people and injure approximately 450,000 people every year, including a high percentage of children. Landmines not only kill and disable individuals but they impede long term reconstruction of war torn regions. Not only are minefields uninhabitable, but they cannot be cultivated or put to productive use because local populations are threatened by the actual and perceived presence of landmines. Unfortunately, local personnel are often enticed into minefields due to the need to cultivate food.
In recent years, the international community has attempted to address the global landmine crisis. The United Nations is coordinating a global effort to survey the state of landmine contamination in landmine affected countries, and private and public groups are undertaking landmine clearance efforts to rid regions of the landmine problem. Unfortunately, it costs only $3.00 to deploy an anti-personnel landmine but approximately $300.00 to remove one. Moreover, landmine clearance is an extremely dangerous profession and it is estimated that more than 80 deminers died in the country of Kuwait after the Gulf War alone.
Unfortunately, there are no inexpensive, mobile vehicles which are suited for operating in vicinity of a minefield. Large tanks are too expensive for many minefield military operations or for demining operations. Meanwhile, smaller and more maneuverable combat vehicles typically do not provide the vehicles"" occupants with the protection to operate in proximity to minefields. Moreover, present vehicles do not provide mobility after they have struck a landmine, leaving the vehicles"" occupants vulnerable to enemy fire or left to walk across an open minefield.
There is thus a definite need for a vehicle which can transport personnel in proximity to a minefield. Moreover, there is a need for a vehicle which can still move once it has struck a landmine.
It would be preferable if the vehicle were mobile and versatile so that it may operate both as a military combat vehicle, a demining vehicle and as a military ambulance. It would also be preferable that the vehicle were reliable and inexpensive to manufacture.
The present invention addresses the aforementioned disadvantages by providing an improved vehicle for traveling through hostile environments. More particularly, the vehicle includes four or more wheels and is constructed to move even if one or two wheels have been disabled, such as being blown off by a landmine or ordnance. Thus, the vehicle of the present invention is ideally suited for operation within the vicinity of a minefield during military combat or demining operations. If one of the wheels encounters a landmine, the wheel assembly is constructed to absorb the forces imparted by the landmine causing the wheel assembly to bend upwardly, or preferably to disengage from the vehicle. As will be explained in greater detail below, the vehicle is constructed to maintain mobility so that if the vehicle strikes a landmine, those within the vehicle can still drive the vehicle to safety.
In a preferred embodiment, the vehicle is hydraulically driven including at least one engine and at least one hydraulic pump for pumping hydraulic fluid to hydraulic motors located at each wheel. The front and rear wheels are non-steerable and driven by separate reversible hydraulic motors. The steering of the vehicle is accomplished by operating driver located hand levers, foot pedals or a steering wheel to controllably direct hydraulic fluid from the hydraulic pump to the hydraulic motors to selectably control the rotational velocity of the wheels on each side of the vehicle. An increase in rotational velocity of wheels on one side of the vehicle relative to the rotational velocity on the other side of the vehicle cause the vehicle to turn in the opposite direction. In fact, the vehicle can rotate within the length of its wheel base by causing the left wheels to rotate at the same speed in the opposite direction as the right wheels of the vehicle.
Vehicle braking is also provided utilizing the hydraulic system. Breaks prone to wear are thereby eliminated.
Preferably, the suspension system is also hydraulic and controllable. The suspension system includes a hydraulic actuator at each of the wheels which support the mass of the vehicle relative to the wheel assemblies. By controllably directing fluid to each of the actuators, the ground clearance of the vehicle can be varied for different road conditions. Moreover, added fluid can be sent to the actuators where the vehicle is carrying additional weight.
Of importance, the vehicle of the present invention is constructed to be capable of movement even if the vehicle encounters a landmine resulting in one or two wheels being blown off. To this end, the suspension system preferably includes control arms at each wheel which extend the wheels laterally away from the chassis and body of the vehicle. Preferably, the control arm are constructed to position the centerline of the wheels at least a twelve (12) inches away from the chassis of the vehicle. Even more preferably, the length of the control arms cause the centerline of the wheels to be positioned at least eighteen (18) to thirty-six (36) inches from the chassis. This is contrary to the constructions of typical suspension systems of military vehicles wherein the centerline of the wheels is positioned within the chassis, or at least as close to the frame as possible to minimize the vehicles profile. However, the vehicle of the present invention moves the wheels away from the vehicle""s chassis in an effort to localize the effects of a wheel striking a landmine as far from the vehicle chassis as possible. Thus, upon the vehicle""s wheel striking a landmine, the forces of the explosion are primarily absorbed by the suspension control arm causing the control arm to bend, or preferably, to xe2x80x9cbreakawayxe2x80x9d from the vehicle.
Projecting through the control arm from each wheel""s hydraulic motor is an axle which connects to the respective wheel. Activation of the hydraulic motor causes the axle to rotate its corresponding wheel. To provide xe2x80x9cbreakawayxe2x80x9d wheels, in a preferred embodiment, the suspension system and axle include a plurality of shear pins which are constructed to shear at specific shear loads. The shear pins connect the vehicle""s frame to the suspension control arms, and connect the hydraulic motors to their corresponding drive axles so that upon the vehicle""s wheel encountering a substantial force, such as one exerted by encountering a landmine, the shear pins are constructed to shear causing the wheel assembly, axle and control arms to disengage from the vehicle.
The vehicle is also provided with a skid plate on the bottom of the vehicle, or with a substantially smooth or unencumbered underside. Upon disengagement of a wheel assembly from the vehicle, the vehicle does not have any sharp edges where the wheel assembly has been removed which would significantly impair the ability of the remaining three wheels to move the vehicle.
In a preferred embodiment, the vehicle is also ideally constructed to function as a combat ambulance. To this end, the vehicle includes a portal and doors on the vehicle""s underside so as to permit objects to pass through the door from the outside of the vehicle to within the vehicle""s interior. To retrieve an injured soldier from a combat environment, the vehicle adjusts its suspension so that it has sufficient ground clearance so as to drive directly over a person when the person is lying in the prone position. The vehicle then drives over the person with the bottom doors of the vehicle open. The person can then be pulled to within the interior of the vehicle without persons within the vehicle being vulnerable to hostile fire.
Other features and advantages of the present invention will be appreciated by those skilled in the art upon reading the detailed description which follows with reference to the attached drawings.